I'd be leery of storing passwords on a portable device for fear of what would happen should the device get out of my hands. It does get to be a hassle, though, entering in multiple passwords for various sites.

Yes, there is that risk. My iPad is password protected by a long password, and it's set to delete all it's data after too many failed attempts. But it's not 100% safe, there is a 15 minute lag before it asks for a password.